List of United States senators from Iowa

Current delegation

Iowa was admitted to the Union on December 28, 1846, and elects United States senators to class 2 and class 3. The state's current U.S. senators are Republicans Chuck Grassley (serving since 1981) and Joni Ernst (serving since 2015). Chuck Grassley is Iowa's longest-serving senator (since 1981).

List of senators

#	Senator	Party	Dates in office	Electoral history	T	C	T	Electoral history	Dates in office	Party	Senator	#
Class 2 Class 2 U.S. senators belong to the electoral cycle that has recently been contested in 2002, 2008, 2014, and 2020. The next election will be in 2026.						C	Class 3 Class 3 U.S. senators belong to the electoral cycle that has recently been contested in 2004, 2010, 2016, and 2022. The next election will be in 2028.
Vacant			Dec 28, 1846 – Dec 7, 1848	Legislature failed to elect.^[1]	—	29th	—	Legislature failed to elect.^[1]	Dec 28, 1846 – Dec 7, 1848	Vacant
Vacant			Dec 28, 1846 – Dec 7, 1848	Legislature failed to elect.^[1]	—	30th	—	Legislature failed to elect.^[1]	Dec 28, 1846 – Dec 7, 1848	Vacant
1	George W. Jones	Democratic	Dec 7, 1848 – Mar 3, 1859	Elected in 1848.	1	30th	1	Elected in 1848.	Dec 7, 1848 – Feb 22, 1855	Democratic	Augustus C. Dodge	1
						31st	2	Re-elected in 1849. Resigned to become U.S. Minister to Spain, having lost re-election.
						32nd
				Re-elected in 1852. Lost renomination.	2	33rd
						33rd			Feb 22, 1855 – Mar 3, 1855	Vacant
						34th	3	Elected in 1855. Elected invalidated, as the Iowa Senate had not participated in it.	Mar 4, 1855 – Jan 5, 1857	Free Soil	James Harlan	2
									Jan 5, 1857 – Jan 29, 1857	Vacant
								Re-elected to finish his vacant term.	Jan 29, 1857 – May 15, 1865	Republican	James Harlan
						35th
2	James W. Grimes	Republican	Mar 4, 1859 – Dec 6, 1869	Elected in 1858.	3	36th
						37th	4	Re-elected in 1860. Resigned to become U.S. Secretary of the Interior.
						38th
				Re-elected in 1864. Resigned due to ill health.	4	39th
									May 15, 1865 – Jan 13, 1866	Vacant
								Elected to finish Harlan's term.^[2] Lost nomination for the next term.	Jan 13, 1866 – Mar 3, 1867	Republican	Samuel J. Kirkwood	3
						40th	5	Elected in 1866.^[3] Lost re-election.	Mar 4, 1867 – Mar 3, 1873	Republican	James Harlan	4
						41st
Vacant			Dec 6, 1869 – Jan 18, 1870
3	James B. Howell	Republican	Jan 18, 1870 – Mar 3, 1871	Elected to finish Grimes's term. Retired.
4	George G. Wright	Republican	Mar 4, 1871 – Mar 3, 1877	Elected in 1870. Retired.	5	42nd
						43rd	6	Elected in 1872.^[4]	Mar 4, 1873 – Aug 4, 1908	Republican	William B. Allison	5
						44th
5	Samuel J. Kirkwood	Republican	Mar 4, 1877 – Mar 7, 1881	Elected in 1876 or 1877. Resigned to become U.S. Secretary of the Interior.	6	45th
						46th	7	Re-elected in 1878.^[5]
						47th
6	James W. McDill	Republican	Mar 8, 1881 – Mar 3, 1883	Appointed to continue Kirkwood's term. Elected in 1882 to finish Kirkwood's term.^[6] Retired.		47th
7	James F. Wilson	Republican	Mar 4, 1883 – Mar 3, 1895	Elected in 1882.^[7]	7	48th
						49th	8	Re-elected in 1884.^[8]
						50th
				Re-elected in 1888. Retired.	8	51st
						52nd	9	Re-elected in 1890.^[9]
						53rd
8	John H. Gear	Republican	Mar 4, 1895 – Jul 14, 1900	Elected in 1894.^[10] Re-elected in 1900,^[11] but died.	9	54th
						55th	10	Re-elected in 1896.^[12]
						56th
Vacant			Jul 14, 1900 – Aug 22, 1900
9	Jonathan P. Dolliver	Republican	Aug 22, 1900 – Oct 15, 1910	Appointed to finish Gear's term.
				Appointed to begin the vacant term. Elected in 1902 to finish the vacant term.^[13]	10	57th
						58th	11	Re-elected in 1902.^[14] Renominated in 1908 but died before the general election.
						59th
				Re-elected in 1907. Died.	11	60th
									Aug 4, 1908 – Nov 24, 1908	Vacant
								Elected to finish Allison's term.	Nov 24, 1908 – Jul 30, 1926	Republican	Albert B. Cummins	6
						61st	12	Re-elected in 1909.
Vacant			Oct 15, 1910 – Nov 12, 1910
10	Lafayette Young	Republican	Nov 12, 1910 – Apr 11, 1911	Appointed to continue Dolliver's term. Lost election to finish Dolliver's term.
10	Lafayette Young	Republican	Nov 12, 1910 – Apr 11, 1911			62nd
11	William S. Kenyon	Republican	Apr 12, 1911 – Feb 24, 1922	Elected to finish Dolliver's term.		62nd
				Re-elected in 1913.	12	63rd
						64th	13	Re-elected in 1914.
						65th
				Re-elected in 1918. Resigned to become Judge of the U.S. Court of Appeals.	13	66th
						67th	14	Re-elected in 1920. Lost renomination, then died.
12	Charles A. Rawson	Republican	Feb 24, 1922 – Dec 1, 1922	Appointed to continue Kenyon's term. Retired when his successor was elected.
13	Smith W. Brookhart	Republican	Dec 1, 1922 – Apr 12, 1926	Elected to finish Kenyon's term.
				Elected to finish Kenyon's term.		68th
				Re-elected in 1924. Lost election challenge.	14	69th
14	Daniel F. Steck	Democratic	Apr 12, 1926 – Mar 3, 1931	Successfully challenged his predecessor's election. Lost re-election.
									Jul 30, 1926 – Aug 7, 1926	Vacant
								Appointed to continue Cummins's term. Elected in 1926 to finish Cummins's term.^[15] Retired.	Aug 7, 1926 – Mar 3, 1927	Republican	David W. Stewart	7
						70th	15	Elected in 1926. Lost renomination and then lost re-election as an Independent.	Mar 4, 1927 – Mar 3, 1933	Republican	Smith W. Brookhart	8
						71st
15	L. J. Dickinson	Republican	Mar 4, 1931 – Jan 3, 1937	Elected in 1930. Lost re-election.	15	72nd
						73rd	16	Elected in 1932. Died.	Mar 4, 1933 – Jul 16, 1936	Democratic	Louis Murphy	9
						74th		Elected in 1932. Died.	Mar 4, 1933 – Jul 16, 1936	Democratic	Louis Murphy	9
									Jul 16, 1936 – Nov 3, 1936	Vacant
								Elected to finish Murphy's term.	Nov 3, 1936 – Jan 3, 1945	Democratic	Guy Gillette	10
16	Clyde L. Herring	Democratic	Jan 3, 1937 – Jan 3, 1943	Elected in 1936. Did not take seat until Jan 15, 1937 in order to remain Governor of Iowa. Lost re-election.	16	75th		Elected to finish Murphy's term.
						76th	17	Re-elected in 1938. Lost re-election.
						77th
17	George A. Wilson	Republican	Jan 3, 1943 – Jan 3, 1949	Elected in 1942. Did not take seat until Jan 14, 1943 in order to remain Governor of Iowa. Lost re-election.	17	78th
						79th	18	Elected in 1944.	Jan 3, 1945 – Jan 3, 1969	Republican	Bourke B. Hickenlooper	11
						80th
18	Guy Gillette	Democratic	Jan 3, 1949 – Jan 3, 1955	Elected in 1948. Lost re-election.	18	81st
						82nd	19	Re-elected in 1950.
						83rd
19	Thomas E. Martin	Republican	Jan 3, 1955 – Jan 3, 1961	Elected in 1954. Retired.	19	84th
						85th	20	Re-elected in 1956.
						86th
20	Jack Miller	Republican	Jan 3, 1961 – Jan 3, 1973	Elected in 1960.	20	87th
						88th	21	Re-elected in 1962 Retired.
						89th
				Re-elected in 1966. Lost re-election.	21	90th
						91st	22	Elected in 1968. Retired.	Jan 3, 1969 – Jan 3, 1975	Democratic	Harold Hughes	12
						92nd
21	Dick Clark	Democratic	Jan 3, 1973 – Jan 3, 1979	Elected in 1972. Lost re-election.	22	93rd
						94th	23	Elected in 1974. Lost re-election.	Jan 3, 1975 – Jan 3, 1981	Democratic	John Culver	13
						95th
22	Roger Jepsen	Republican	Jan 3, 1979 – Jan 3, 1985	Elected in 1978. Lost re-election.	23	96th
						97th	24	Elected in 1980.	Jan 3, 1981 – present	Republican	Chuck Grassley	14
						98th
23	Tom Harkin	Democratic	Jan 3, 1985 – Jan 3, 2015	Elected in 1984.	24	99th
						100th	25	Re-elected in 1986.
						101st
				Re-elected in 1990.	25	102nd
						103rd	26	Re-elected in 1992.
						104th
				Re-elected in 1996.	26	105th
						106th	27	Re-elected in 1998.
						107th
				Re-elected in 2002.	27	108th
						109th	28	Re-elected in 2004.
						110th
				Re-elected in 2008 Retired.	28	111th
						112th	29	Re-elected in 2010.
						113th
24	Joni Ernst	Republican	Jan 3, 2015 – present	Elected in 2014.	29	114th
						115th	30	Re-elected in 2016.
						116th
				Re-elected in 2020.	30	117th
						118th	31	Re-elected in 2022.
						119th
To be determined in the 2026 election.					31	120th
To be determined in the 2026 election.					31	121st	32	To be determined in the 2028 election.
#	Senator	Party	Years in office	Electoral history	T	C	T	Electoral history	Years in office	Party	Senator	#
Class 2						C	Class 3

Notes

^ ^a ^b Clark, pp. 17–46, 72–79.
^ Clark, p. 141: Kirkwood 118 votes, John Thompson Stoneman (Democratic) 20
^ Clark, p. 141: Harlan 118 votes, Henry Hoffman Trimble (Democratic) 20
^ Clark, p. 167.
^ Clark, p. 185: Allison 104 votes, Daniel F. Miller 35 votes, E. N. Gates 3 votes.
^ Clark, p. 199: Moses M. Ham and Daniel Campbell lost.
^ Clark, p. 199: La Vega G. Kinne and Daniel P. Stubbs lost.
^ Clark, p. 209: Allison 90 votes, Benton J. Hall 48 votes, D. M. Clark 10 votes, La Vega G. Kinne 1 vote.
^ Clark, p. 221: Allison 79 votes, Samuel L. Bestow (Democratic) 63 votes, William Larrabee 8 votes.
^ Clark, p. 234: Gear beat Democrat Horace Boies by votes unknown.
^ Clark, p. 245: Gear 111 votes, Fred E. White (Democratic) 32 votes.
^ Clark, p. 238: Allison 118 votes, Washington I. Babb (Democratic) 25 votes, Frank Q. Stuart 1 vote.
^ Clark, p. 247: Dolliver 119 votes, John J. Seerley (Democratic) 20 votes.
^ Clark, p. 247: Allison 119 votes, Edward Hankinson Thayer (Democratic) 20 votes.
^ Byrd, p. 107.